Dear all,
It was a pleasure to meet you at Iowa State University. Two days ago I
submitted two experimental packages to CRAN (hope it will be there soon):
rindex: quick indexing of large objects (currently only character, see ?index)
regtest: some first support for automated regression testing (heavily used in
\dontshow{} section of ?index)
With rindex you can for example
i <- index(rownames(someDataFrame))
# then this
someDataFrame[match(fewRowNames, i),]
# is much faster than that
someDataFrame[match(fewRowNames, rownames(someDataFrame)),]
# which still is much faster than
someDataFrame[fewRowNames, ]
# the latter being surprisingly slow as it can be worked around by match (even
without indexing)
I'd appreciate any comments, especially on the "Open Questions" secion in
?index, in order to
1) extend to all atomic types and be UTF8-safe
2) extend to packages R.huge and/or ff
3) optimally integrate with sort(OK), order(no generic yet) and match(no
generic and dispatch rather needed on second argument)
Both packages were developed under 2.5.1 and I plan to publish them under a
GPL2-QA, a GPL2 clone that obliges users to participate in some kind of
regression testing (to be defined).
Best regards
Jens Oehlschlägel
P.S.
> # some timings using timefactor(regtest)
> library(rindex)
>
> Vec1 <- c(NA, paste('a', 1:1000000, sep=""))
> Vec2 <- c(paste('a', 1:1000000, sep=""), NA)
> iVec1 <- index(Vec1, verbose=TRUE)
user.self sys.self elapsed
sort 7.85 0.01 7.86
tree 0.00 0.00 0.00
> iVec2 <- index(Vec2, verbose=TRUE)
finalized tree
user.self sys.self elapsed
sort 7.78 0 7.79
tree 0.00 0 0.00
>
> timefactor(any(Vec1=="a999"), any(iVec1=="a999"), 10, 100)
finalized tree
nom denom factor
user.self 0.041 0.0036 11.38889
sys.self 0.000 0.0000 NaN
elapsed 0.041 0.0036 11.38889
> timefactor(any(Vec2=="a999"), any(iVec2=="a999"), 10, 100)
nom denom factor
user.self 0.040 0.0036 11.11111
sys.self 0.000 0.0000 NaN
elapsed 0.041 0.0036 11.38889
>
> timefactor(length(match("a999", Vec1)), length(match("a999", iVec1)), 10,
> 1000)
nom denom factor
user.self 0.125 0.00017 735.2941
sys.self 0.000 0.00000 NaN
elapsed 0.125 0.00018 694.4444
> timefactor(length(match("a999", Vec2)), length(match("a999", iVec2)), 10,
> 1000)
nom denom factor
user.self 0.123 0.00015 820.0000
sys.self 0.003 0.00000 Inf
elapsed 0.127 0.00015 846.6667
>
> timefactor(length(match(c("a9","a99","a999","a9999"), Vec1)),
> length(match(c("a9","a99","a999","a9999"), iVec1)), 10, 1000)
nom denom factor
user.self 0.126 0.00022 572.7273
sys.self 0.000 0.00000 NaN
elapsed 0.127 0.00022 577.2727
> timefactor(length(match(c("a9","a99","a999","a9999"), Vec2)),
> length(match(c("a9","a99","a999","a9999"), iVec2)), 10, 1000)
nom denom factor
user.self 0.125 0.00022 568.1818
sys.self 0.002 0.00000 Inf
elapsed 0.126 0.00022 572.7273
>
> # and not too bad with respect to the recent hasNA() / anyNA() thread (once
> the index has been built)
> timefactor(any(is.na(Vec1)), any(is.na(iVec1)), 50, 50)
nom denom factor
user.self 0.0040 0.003 1.333333
sys.self 0.0004 0.000 Inf
elapsed 0.0044 0.003 1.466667
> timefactor(any(is.na(Vec2)), any(is.na(iVec2)), 50, 50)
nom denom factor
user.self 0.0040 0.0036 1.111111
sys.self 0.0008 0.0000 Inf
elapsed 0.0046 0.0034 1.352941
>
> # especially if using a better function for this
> timefactor(any(is.na(Vec1)), length(match(NA, iVec1)), 50, 1000)
nom denom factor
user.self 0.0044 0.00013 33.84615
sys.self 0.0002 0.00000 Inf
elapsed 0.0046 0.00013 35.38462
> timefactor(any(is.na(Vec2)), length(match(NA, iVec2)), 50, 1000)
nom denom factor
user.self 0.0044 0.00014 31.42857
sys.self 0.0000 0.00000 NaN
elapsed 0.0042 0.00014 30.00000
>
> # or ask directly :-)
> timefactor(any(is.na(Vec1)), iVec1$nNA, 50, 10000)
nom denom factor
user.self 0.0044 9e-06 488.8889
sys.self 0.0000 0e+00 NaN
elapsed 0.0044 9e-06 488.8889
> timefactor(any(is.na(Vec2)), iVec2$nNA, 50, 10000)
nom denom factor
user.self 0.0046 1e-05 460.0000
sys.self 0.0000 0e+00 NaN
elapsed 0.0046 9e-06 511.1111
>
> version
_
platform i386-pc-mingw32
arch i386
os mingw32
system i386, mingw32
status
major 2
minor 5.1
year 2007
month 06
day 27
svn rev 42083
language R
version.string R version 2.5.1 (2007-06-27)
# some timings using timefactor(regtest)
library(rindex)
Vec1 <- c(NA, paste('a', 1:1000000, sep=""))
Vec2 <- c(paste('a', 1:1000000, sep=""), NA)
iVec1 <- index(Vec1, verbose=TRUE)
iVec2 <- index(Vec2, verbose=TRUE)
timefactor(any(Vec1=="a999"), any(iVec1=="a999"), 10, 100)
timefactor(any(Vec2=="a999"), any(iVec2=="a999"), 10, 100)
timefactor(length(match("a999", Vec1)), length(match("a999", iVec1)), 10, 1000)
timefactor(length(match("a999", Vec2)), length(match("a999", iVec2)), 10, 1000)
timefactor(length(match(c("a9","a99","a999","a9999"), Vec1)),
length(match(c("a9","a99","a999","a9999"), iVec1)), 10, 1000)
timefactor(length(match(c("a9","a99","a999","a9999"), Vec2)),
length(match(c("a9","a99","a999","a9999"), iVec2)), 10, 1000)
# and not too bad with respect to the recent hasNA() / anyNA() thread (once the
index has been built)
timefactor(any(is.na(Vec1)), any(is.na(iVec1)), 50, 50)
timefactor(any(is.na(Vec2)), any(is.na(iVec2)), 50, 50)
# especially if using a better function for this
timefactor(any(is.na(Vec1)), length(match(NA, iVec1)), 50, 1000)
timefactor(any(is.na(Vec2)), length(match(NA, iVec2)), 50, 1000)
# or ask directly :-)
timefactor(any(is.na(Vec1)), iVec1$nNA, 50, 10000)
timefactor(any(is.na(Vec2)), iVec2$nNA, 50, 10000)
version
--
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